Slurry loader for centrifugal machines



Nov. 17, 1959 R, JQ HusER f SLURRY LOADER F OR CENTRIFUGAL y/(HINES Filed Mayr 24, 1955 wf 'I Arme/vf Ys tate SLURRY LOADER FOR CENTRIFUGAL MACHINES Application May 24, 1955, Serial No. 510,815 3 Claims. (Cl. 210-377) This invention relates to a loading device for centrifugal machines and, more particularly, to a device for feeding a liquid slurry into a rotating centrifugal basket so as to form a charge of uniform thickness in the basket.

in centrifugal work of this nature, a prolonged period of feeding of the slurry generally is necessary in order to form a full load of finely divided solids in the rotating basket. During the loading period the solids accumulate progressively against the basket side wall under the settling effect of centrifugal force, While excess liquid is expelled from the basket through side wall perforations, or through a suitable liquid outlet in the case of an imperforate basket. When a full charge of solids has been formed, the loading is discontinued and centrifugal drying and discharging operations may ensue, to be followed in turn by resumed loading to form a new charge.

It is important during the loading operation to form a practically uniform annular wall of solids against the basket side wall. Otherwise, the degree of drying accomplished will not be uniform, the capacity of the basket will not be fully utilized, and an unbalanced basket condition or even a severe limitation of the rotative speed for drying the charge may result. ln addition to uniformity in the wall of solids, it is important to have the loading operation subject to easy and quick control by the operator so that the loading operation can be discontinued or resumed Without delay.

An object of this invention is to provide a slurry loader fulfilling these needs that is compact and simple in its construction and which operates reliably under either manual or automatic control to forni charges of substantially uniform thickness in the rotating basket of a centrifugal machine.

A loading device according to this invention includes a housing adapted to be mounted in a *fixed position adjacent the opening of a centrifugal basket, and a tube slidable in said housing. The tube has portions extending to opposite sides of said housing, one portion extending outside the basket and forming an inlet for the slurry and another portion extending inside the basket and having a nozzle at its end for delivering slurry to the basket side wall. rifhe housing forms an elongated fluid pressure chamber embracing an intermediate portion of the tube, and this portion of the tube carries a piston which closely fits the chamber and is movable therein by uid pressure. Means are provided for introducing fluid under pressure into the chamber alternately at opposite sides of the piston,.so as to reciprocate the piston and the tube, and the range of movement of the piston is sufficient that slurry discharged from the nozzle during its reciprocation vwill be delivered over substantially the full length of the basket side wall.

Other objects, features and advantages of this invention will become apparent from the following detailed description and the accompanying drawings of an illustrative embodiment of the invention.

In the drawings:

Fig. l is an assembly view, partly in elevation and partly in vertical cross section, illustrating the loading device in operative association with a centrifugal machine;

Fig. 2 is a fragmentary plan view of the loading device as seen in Fig. l; and

Fig. 3 is a vertical cross section on an enlarged scale taken in the direction of arrows 3 3 in Fig. l.

in the arrangement shown for the purpose of illustrating the principles of this invention, there is provided a loading device generally .identified by the reference numeral 1d. The loading device is mounted in operative relation upon a centrifugal machine 11 that is adapted to process the charge material supplied by the loading device.y A part of the curb of the machine is shown at 12, and an upper part of the rotary basket is shown at 13. The basket 13 is suspended in the usual manner from a spindle or shaft 14, which is adapted to be rotated at high speed by suitable means (not shown) in order to separate the liquid and solid constituents of the charge material delivered into the basket.

The loading device lll includes a stationary housing 15 mounted in an aperture 20 in the top of the curb of the machine. An elongated slurry tube 16 is slidably mounted in the housing. This tube extends vertically through the housing l5 in a direction parallel to the axis of rotation of the centrifugal basket 13, with its upper and lower portion 17 and 18 extending from the housing to positions outside and inside the basket, respectively. See Fig. 3. An inlet 19 for liquid slurry is provided at the upper end of the tube, and an outlet nozzle 21 is provided on its lower end. The lower portion 18 extends through the central opening 22 of the basket, and sup ports the outlet nozzle in a position whe-re the nozzle faces an adjacent part of the perforate side wall 23 of the basket and can deliver slurry directly to that wall.

'The housing 15 itself is elongated in a direction parallel to the basket axis, ie., vertically in the illustrated embodiment, and it constitutes a fluid pressure ycylinder in which an intermediate portion of the slurry tube yWorks as a piston during the loading of a slurry through the tube into the basket 13. To this end, as seen in Fig. 3, the inner diameter of the housing 15 is sufficiently larger than the tube that a chamber 26 is formed between the housing and the intermediate portion 30 of the tube 16. Tube portion 3l! is provided with a fixed ring 27 ywhich extends radially toward the inner surface 29 of the housing and carries at its periphery a sealing ring 28 that s slidable along surface 29 in sealed relation thereto. The sealing ring 28 can be a neoprene O ring or the like. The rings 27 and 23 thus constitute a piston fixed to an intermediate portion of the tube, by which thel tube is reciprocable in the housing upon the admission of fluid under pressure into chamber 2-6.

The upper and lower tube portions 17 and 18 are slidable in upper and lower annular caps 31 and 32 secured to the ends of the housing. Each cap is equipped with a bushing 33 in which the respective tube portion is slidable, and with an O ring 34 that forms a pressure tight seal with the tube. A wiper ring 35 is installed near the outer end of each cap to prevent foreign matter from being carried into the bushing and sealing elements.

The housing 15 has upper and lower ports 36 and 37 formed therein to conduct a fluid under pressure, such as compressed air, into or from either end of the chamber 26. As shown in Fig. l, conduits 3S and 39 extend from the ports 35 and 37, respectively, to a four-Way air valve il to which compressed air is supplied through air line 4Z. Valve 41 has a handle 43 which is positionable so las to admit compressed air from line 42' into either of the conduits 38 and 39, and the valve arrangement is such that while it is admitting pressure into one of. the conduits it is venting pressure from the other conduit. Although valve 41 is shown as being manually operated, it is to be understood that it may be of a type that is automatically operated.

As may be noted from Fig. 3, the lower air port 37 of thehousing is located at a point above the curb top 12,. while the housing itself extends downwardly from the latter for a considerable `distance to an end point inside the basket 13. In order to utilize substantially the entire length of the housing chamber 26 for reciprocation of the tube 16, the upper air port 36 communicates directly with the top of that chamber, and the lower air port 37 communicates with the bottom of that chamber through a duct 44 which extends in and along a longitudinal embossment 4S at one side of the housing. By virtue of this construction, the air conduit to port 37 is at an accessible location outside the curb, and the loading device can be removed from the curb simply by removing the bolts 46 which hold the housing to the curb top.

Air llow controllers 47 and 4S of known construction are provided in the upper and lower air conduits 38 and 39, respectively, in order to regulate the rate of flow of compressed air from each end of the chamber 26. In this Way, the speed of movement of the slurry tube is regulated to a desired value in each direction or stroke of its rcciprocation. Each ow controller has a restricted orifice therein which restricts the flow of air 'through the corresponding conduit in the direction away from the housing chamber. The size of this oriiice is adjustable by changing the setting of an adjustment screw 49 or 51. When the air flow in either conduit is in the direction towards the housing chamber, a valve opens in the corresponding flow controller to remove the restriction otherwise imposed by the restricted orifice.

The nozzle 21 forms a slurry outlet or orifice 24 that is elongated in the direction of the movement of tube 16. As shown in Fig. 1, this outlet is convexly curved along its outer side, so that the slurry leaving the nozzle will be discharged in a fan-shaped stream or spray. The lateral direction of the stream can be changed by loosening the lock nut 25, rotating the nozzle with respect to the tube, and then retightening the lock nut. Preferably, the nozzle is directed so that the stream is pointed somewhat in the direction of rotation of the basket.

Nozzle 21 is held in the desired position during the reciprocation of tube 16 by means of a guide rod 52 which is iixed to a lug 52a on the upper end of housing 15 and extends upwardly therefrom into sliding engagement with a bushing S4 formed in a lug 53 on the upper end of tube 16. As the tube is reciprocated in the housing, bushing 54 slides up and down the guide rod, thus maintaining the tube in a fixed angular relation to the housing and the centrifugal basket 13.

The slurry to be treated in the machine may be held in a tank S5 located at one side of and well above the basket assembly. An outlet 56 in the bottom of the tank may be controlled by a plug valve 58 and connected through a hose S7 with the slurry inlet 19 at the top of tube 16. When valve 53 is opened, slurry in the tank will ow directly into and through the loading tube and will be delivered to the basket side wall in a fanshaped ow issuing continuously from the nozzle outlet 24 at the lower end of the tube.

In the use of the loading device, the operations may be as follows:

The basket 13 is rotated at a speed suitable for the loading operation, and slurry is supplied to the inlet 19 of tube 16 under a suitable pressure head. The slurry ows through the tube and leaves nozzle 21 in a fanshaped spray or stream. At the same time, valve 41 is operated so as to admit air pressure `alternately to the upper and lower ends of the chamber 26 in housing 15. This causes the piston 27 and tube 16 to reciprocate in the housing to the extent indicated in Fig. 1, wherein the tube inlet 19 is illustrated in full lines in its uppermost position, and by dotted lines in its lowermost position. The reciprocatory motion of the nozzle accompanying this motion of the tube causes the fan-shaped tlow of slurry to reach all parts of the basket side wall, so that the slurry is deposited evenly on the side wall and forms a charge of substantially uniform thickness.

it will be understood that the new features herein disclosed and set forth in the appended claims may be employed in ways and forms differing from those of the embodiment described above and illustrated in the drawings, without departing from the contribution of this invention.

What is claimed is:

1. A device for loading a liquid slurry into a centrifugal basket mounted on a vertical spindle for rotation within a surrounding curb having an end closure extending over the top of the basket, comprising an elongated tubular housing forming a vertically elongated huid pressure chamber, an elongated slurry tube extending vertically and slidably through said chamber, means on an outside part of said housing intermediate its ends for mounting the housing in a xed position upon said end closure with one portion of the housing extending upwardly away from said basket and the other portion extending downwardly through said end closure to a location within the contines of the basket, an upper end portion of said tube extending beyond said one portion of the housing and forming an inlet for the slurry, the lower end portion of said tube extending from said other portion of the housing and carrying at its end a nozzle for delivering slurry to the side wall of the basket, a piston iixed to a portion of said tube within said chamber and movable by uid pressure in said chamber to move said tube, a fluid pressure conduit extending through said one portion of said housing into the end of said chamber remote from the basket, another Huid pressure conduit extending from outside said one portion of said housing along said other portion thereof and thence into the end of said chamber within said basket, and means for supplying uid under pressure alternately into said conduits for reciprocating said tube to distribute slurry from said nozzle evenly along the basket side Wall.

2. A slurry loading device as described in claim 1, the length of said chamber being substantially less than the length of the basket side wall and said nozzle having a slurry outlet elongated in the direction of its axis of movement to form a fan-shaped ow of slurry, the height of said flow plus the range of movement of said piston in said chamber being suicient to deliver the slurry evenly over substantially the full length of the basket side wall.

3. A slurry loading device as described in claim 2, said slurry outlet being in the form of a vertical slit convexly curved along its outer side and lying in a plane radial to said axis.

References Cited in the tile of this patent UNITED STATES PATENTS 

